sprocket
#3
#5
RE: sprocket
I was told from the company i bought my sprockets from that the speedo stock is about 10% higher and with the kit i ordered it drops it down to 2% higher
http://cgi.ebay.com/ebaymotors/HONDA...QQcmdZViewItem
http://cgi.ebay.com/ebaymotors/HONDA...QQcmdZViewItem
#6
#7
RE: sprocket
You can change it with a speedo calibrator. If you search the forum you can find links to companies that make them. You can find out how much it is off from stock by seeing what percentage you changed from stock gearing (one tooth out of sixteen) .0625=6.2%. So if you went down one tooth on the front your speed will change by 6%. So if your speedo is reading 100 mph you are doing 106 mph according to your factory speedo.
#8
RE: sprocket
yeah, one such re-calibrator is the "Speedo Healer" and another is the "Yellow Box". Google 'em up.
As for real world figures on the down-one-tooth-up-front mod, I recently went by a few local radar boards on the freeway (those big white boxes with the sign "Your Speed is" and the radar readout). On my F4i with the 15/46 mod, the speedo error is somewhere in the 11-15% range ( I do not have a calibrator). At 91 indicated (on my speedo), radar read 81. At 75 indicated, radar read 65. These two runs were on two different radar boxes. It could be slight error in calibration of the radars. It could be that my aerodynamic tuck was a little more efficient going by the first radar. Or a combination of calibration error and tuck position (not to mention that wind and/or incline/decline may reduce/increase RPMs needed to achieve indicated speed -- and doesn't a reading off the countersprocket just measure revolutions?). Along with frontal area of bike and rider(tuck), drag is proportional to square of velocity so that affects actual speed versus indicated speed (if reading is off the countersprocket) since it takes more power and thus more RPMs to overcome rolling resistance, right?
As for real world figures on the down-one-tooth-up-front mod, I recently went by a few local radar boards on the freeway (those big white boxes with the sign "Your Speed is" and the radar readout). On my F4i with the 15/46 mod, the speedo error is somewhere in the 11-15% range ( I do not have a calibrator). At 91 indicated (on my speedo), radar read 81. At 75 indicated, radar read 65. These two runs were on two different radar boxes. It could be slight error in calibration of the radars. It could be that my aerodynamic tuck was a little more efficient going by the first radar. Or a combination of calibration error and tuck position (not to mention that wind and/or incline/decline may reduce/increase RPMs needed to achieve indicated speed -- and doesn't a reading off the countersprocket just measure revolutions?). Along with frontal area of bike and rider(tuck), drag is proportional to square of velocity so that affects actual speed versus indicated speed (if reading is off the countersprocket) since it takes more power and thus more RPMs to overcome rolling resistance, right?
#9
RE: sprocket
Whether you're going downhill, uphill or whatever, your counter sprocket will always rotate at the same ratio relative to the rear sprocket because they are directly linked through the chain. Yes, it does take less POWER to achieve XX MPH downhill, however, the sprocket rotation RPMs are the same.